US President Donald Trump has blasted the 2015 Iran nuclear deal with world powers as “incompetently drawn,” fueling speculations that he is going to “decertify” the landmark agreement achieved under his predecessor, Barack Obama.

“I think it was one of the most incompetently drawn deals I’ve ever seen,” Trump told Fox News on Wednesday night.

“$150 billion given — we got nothing. They got a path to nuclear weapons very quickly, and think of this one — $1.7 billion in cash — this is cash out of your pocket,” Trump claimed.

“So this is the worst deal,” he added. “We got nothing. We got nothing.”

The Republican head of state was referring to the Obama administration’s $1.7 billion payment to settle in 2016 legal disputes over a sale of military equipment to Tehran before the 1979 Islamic Revolution.

Iranian officials have already rejected Trump’s other claim that the country’s assets frozen in overseas banks due to sanctions amounted to around $150 billion.

The Central Bank of Iran (CBI) – to which the bulk of frozen assets belongs – says the figure stands around $29 billion along with $6-$7 billion in government revenues from crude oil sales which would be returned to the administration of President Hassan Rouhani once released.

Under the nuclear deal, known as the Joint Comprehensive Plan of Action (JCPOA), Iran and the P5+1 group of countries—the US, the UK, France, China, Russia and Germany. Tehran agreed to put certain restrictions on its peaceful nuclear program in exchange for lifting of all nuclear-related sanctions.

Trump, who was vocally opposed to the deal during his last year presidential campaign, has desperately sought a pretext to scrap or weaken the JCPOA and get rid of the limits it imposes on the US ability to pursue more hostile policies against Iran.

After certifying Iran’s compliance on two different occasions, Trump is reportedly planning to declare this time that the nuclear deal is not in the national interest of the US, leaving it to a reluctant Congress to decide whether the sanctions relief should be extended.

This is while the International Atomic Energy Agency (IAEA) has repeatedly confirmed Iran’s compliance.

Democrats warn against leaving JCPOA

Former US Secretary of State John Kerry, who played a key role in the marathon talks that preceded the deal, met with Democrats on Wednesday to address their concerns.

New York Representative Eliot Engel, who serves as the top Democrat on the House Foreign Affairs Committee, said the former Obama administration officials and the foreign ambassadors attending the meeting all agreed that Washington should stay in the deal.

California Representative Adam Schiff, the ranking member on the House Intelligence Committee, said “It would certainly mean a loss of our standing in the world if one administration won’t honor an agreement by the last. But hopefully it won’t come to that.”

Earlier this month, at least 180 members of the US Congress called on Trump in a letter to recertify the deal unless he can present “credible evidence of a material breach” of it by Tehran.